Pipe releasing device



SEM. 24V, 1946.

O. J. MGCLVJLLOUGH PIPE RELEASING DEVICE Fil-ed July 26, 1945 .INVENTORT gGULLOUGH @JIM wmmwmm E; E m *4% /9 rfb/mfr Patented Sept. 24, 1946 UNITED STATE PIPE RELEASING DEVICE Otis J. McCullough, Houston, Tex., assignor to McCullough Tool Company, Houston, Tex.

Application July 26, 1943, Serial No. 496,140

(Cl. 16S-1) 1 claim. l

The invention relates to a pipe releasing device which is particularly adapted for use in a string of pipe which is stuck or lodged in a well bore at an inaccessible location and is useful in jarring loose a threaded connection so as to permit unscrewing of the pipe.

In the drilling of wells by the rotary method a string of drill pipe is made up of sections threaded together with couplings and this string of pipe serves to advance the bit by rotating the bit on the bottom of the well bore. In some instances the Ibit may become lodged in a lissure or crevice or may be otherwise stopped from rotating and the operator on the surface may continue to rotate the pipe and twist off the pipe somewhere in the well bore. In other instances the pipe may become stopped due to caving or coagulation of the drilling mud. Under these circumstances it is desirable to unscrew one or more sections of the drill pipe and remove the same from the well so as to eventually salvage the pipe. While drill pipe has been mentioned, other types of pipe such as tubing or casing are also utilized in the well bore.

The present invention concerns itself with the setting of the tool at the desired threaded coupling which is to be released, the application of a torque tending to unscrew the pipe and then the creation of a high pressure blast at the threaded coupling which will tend to jar the coupling and in this manner to loosen the threads.

It is therefore one of the objects of the invention to provide a pipe releasing tool which can be located so as to apply a jar at a threaded connection in a well bore.

Another object of the invention is to provide a device for latching the pipe releasing tool at the elevation of the threaded coupling to be released.

Still another object of the invention is to provide a, pipe releasing tool wherein a primer serves to set oi a charge of explosive to provide a source of high pressure to jar the pipe.

Another object of the invention is to provide an electrically red pipe releasing device wherein the electric contacts are sealed by confining a resilient material and applying a, pressure thereto.

Another object of the invention is to control the pressure at which a pipe releasing device will discharge a, pressure therefrom against the pipe to be released.

Other and further objects of the invention will be readily apparent when the following description is considered in connection with the accompanying drawing wherein:

Fig. 1 is a side elevation of the tool located in a string of pipe in a well bore and ready to be actuated to release, the pipe. v

Figs. 2 and 3 are vertical sectional views which form a continuation one with the other and illustrate the internal construction of the tool.

Fig. 4 is a transverse verticalv section taken through the explosive chamber and the locating springs of Fig. 3.

Fig. 5 is a broken detail sectional view illustrating a plug construction which will'determine the pressure at which the jar is releasedagainst the pipe.

In Fig. l. a string of pipe 2 has been -illustrated which may be made up of the pipe sections 3 and 4 which are threaded together by a coupling. As seen in Fig. l the ends of the pipe 3 and 4 do not usually come in close contact with each other, but may provide an open space 6 inside of the coupling 5. In this manner the lower end I of the pipe 4 forms a shoulder in the threaded con nection.

A pipe releasing device constitutes a tool IIJ which is suspended by means of a cable I I in the pipe in the well bore. This cable II serves to manipulate the tool by lowering and raising it in the well bore.

The tool I0 has a plurality of springs I2 circumferentially arranged thereon as seen in Fig. 4

which normally extend outwardly 4beyond the pethe cable II until the springs I2 snap into a threaded coupling. This prevents further upward movement of the tool and the operator is advised that his tool is anchored in a threaded coupling. This arrangement of structure is seen in Fig. 1. The springs I2 may be connected to the tool by the screws I3.

The tool I0 is made up of a cap I4 which is threaded at I5 into the Ibonnet I6. This bonnet I 6 is in turn connected to the nipple I1 which is threaded at I8 to the housing I9. A foot piece or tail pipe 20 may be carried by the lower end of the housing if desired.

As seen in Fig. 2 the cable II extends through the passage 22 in the cap I4 and into the bonnet I6. This cable may preferably carry an electric contact 23 which is anchored in a sealing tool which' might short circuit the y#wire 26 itis desirable to set up and maintain inside the tool a pressure in excess of the pressure expected to be encountered in the well bore. To accomplish this the plugs 35 of material have been inserted through the openings 3l in the side of the bonnet and the set bushings 32 may be screwed into the openings in order to compress the plugs 3) and the packing material 24. In this manner th'e desired pressure may be set up around the wire 26 to prevent any leakage into the tool.

Fig. 3 shows the nipple l1 as having the lower end of the bonnet E6 threaded thereinto so that the contact 23 projects into the primer chamber 34 in the nipple Il. This primer chamber is arranged to receive an adapter 35 and the primer 36 which is held in position by a spring 3l. This primer may be of any suitable type which is arranged to be red when a vflow of current occurs through the-fconta'ct-l so as to ignite the primer. The ri-ng of this primer discharges re into the chamber 39 from whence it flows through the passage 46 into the explosion chamber 4l. This passage l0 is of relatively small diameter so as to conduct the fire from the primer into the explosion chamber.

The explosion chamber Il! is disposed in the housing i9 and is arranged to contain a charge 43 of gun powder or other suitable explosive which will be detonated by the re from the passage 49. It seems obvious that the size of this charge can he varied in accordance with circumstances encountered. A lateral outlet 45 from the explosion chamber is shown as being closed by the plug or disk 46 which is firmly fitted therein. When the detonation occurs this plug will be blown from the opening 45 against the inside of the lcoupling as will be apparent from Fig. 1. This plug 46 may t snugly in the opening so that a predetermined pressure will have to build up in the explosion chamber before the plug is dislodged. The small area'of the passage 4 46 prevents escape of any substantial amount of the pressure from the explosion chamber.

Fig. 4 shows three of these openings or discharge outlets so that a uniform jar is applied to the circular threads.

Fig. 5 shows a modiiied type of plug 46 in the form of a cylindrical gure 41 which may be a phenolic member which is driven into the position seen in Figure 5 and can only be dislodged by theV application of a tremendous force.

In operation the tool willbe lowered through Hthe pipe l to approximately the position of the coupling which is to be unscrewed. The tool is then moved upwardly until the spring ngers catch in the threaded coupling as seen in Fig. 1. A torque is then preferably applied to the pipe l in any suitable manner tending to unscrew the threads of the coupling. While this torque is applied the tool will be red so as to apply a sharp jarring action to the coupling which will tend to loosen the threaded connection so that the torque will unscrew the coupling.

Broadly the invention contemplates a tool for applying a jarring action to a pipe in a well bore wh'erein the tool can be accurately located at the positionl where the jarring action is to be applied.

What is claimed is:

Apparatus for use in well tubing within a well bore to facilitate unthreading of sections of Well tubing at a joint formed by an internally threaded female coupling member surrounding and threadedly connected to'externally threaded ends of tubing sections with the tubing section ends spaced from each other, comprising a housing arranged to be lowered into the well tubing and having an explosion chamber therein, a charge of explosive in said chamber, a plurality of pressure outlet ports in said housing extending from said chamber radially outward in a single substantially horizontal plane to discharge the products of detonation of the explosive in a plurality of substantially horizontally and radially directed jets, means on said housing arranged to contact the end of one of th'e tubing sections for positioning the housing with said outlet ports and the jets of explosive products directed at circumferentially'spaced portions of the interior surface of said female coupling member between the spaced ends of the tubing sections, and means for detonating saidv explosive.

OTIS J. MCCULLOUGH. 

